Identification of power line outages

This paper considers the problem of identifying power line outages throughout an electric interconnection based on changes in phasor angles observed at a limited number of buses. In existing approaches for solving the line outage identification problem the unobserved phasor angle data is ignored and identification is based on the observed phasor angles extracted from the data. We propose, instead, a least-squares approach for estimating the unobserved phasor angles, which is shown to yield a solution to the line outage identification problem that is equivalent to the solution obtained with existing approaches. This equivalence suggests an implementation of the solution to the line outage identification problem that is computationally more efficient than previous methods. A natural extension of the least-squares formulation leads to a generalization of the line outages identification problem in which the grid parameters are unknown.